1. Field of the Invention
The invention relates to motors which use a pressurized fluid such as air or steam and in particular to such a motor having an array of pistons radially reciprocal in a rotating housing wherein the pistons exert a driving force against a stationary eccentric surface, and the motor's output shaft is operatively coupled to the rotating housing.
2. Description of the Prior Art
Radial motors which incorporate pistons which act radially outwardly against a cam surface to impart rotary motion to a rotatable housing carrying the pistons are well known. Such a motor is, for example, disclosed in U.S. Pat. No. 663,716 to C. H. Asling et al. In such motors, power is derived from a pressurized fluid, such as compressed air or steam. The pressurized fluid is used to force a piston radially outwardly within a rotating housing. The radially outwardly disposed ends of the pistons act by means such as rollers or the like against an eccentric cam surface formed on the inside of a housing which encloses the rotary housing. As the pistons act against the cam surface, they extend and retract reciprocally and impart rotational force on the housing to produce power.
However, radial motors of the general type herein disclosed have heretofore lacked the mechanical refinement necessary to render such a motor compact relative to its displacement, and exhibit deficiencies in their porting and the mechanical coupling between the pistons and the eccentric cam shaft surface necessary to provide maximum efficiency and economy in their construction. Accordingly, there exists a need for an improved rotary motor or engine incorporating radially reciprocal pistons acting against an external eccentric cam surface in which the arrangement of the pistons, ports, and piston drive elements are arranged for maximum efficiency.